Hypothermia in lambs
Hypothermia is a big killer in little lambs particularly in extreme weather conditions. However, warm boxes and administering a glucose injection can help boost lamb survival.
Hypothermia will kill the lamb long before disease will get the opportunity to do so. When the lamb is born it has very limited energy reserves.
In order to utilise these energy reserves to generate heat, the ewe must receive adequate selenium supplementation during pregnancy. If selenium levels are inadequate the newborn lamb will have a reduced ability to keep itself warm, increasing the chances of hypothermia.
Hungry lambs are easy to identify but can cause a major headache at lambing time. In most instances, the newborn lamb is enthusiastic in searching for the teat. If this is unsuccessful the lamb quickly becomes weak and is incapable of making much effort to suckle.
These lambs will become gaunt, hollow and stand with a hunched appearance. It will take two to three days for these lambs to die. This means that there should be ample opportunity to detect and treat at risk lambs.
However, the window of opportunity to remedy this situation is shortened in cold, draughty or wet conditions. A quick post-mortem examination will confirm any suspicions you may have that a lamb died from hunger.
Kidney’s are key with hypothermia in lambs
The key are the kidneys. If these are not surrounded by fat it is most likely death due to starvation. Hunger is therefore often combined with hypothermia.
Between 37-39C we refer to the lamb as being moderately hypothermic, and this is quite easy to correct at this stage. Below 37C, the lamb is said to be severely hypothermic and is more difficult to treat. So it goes without saying that the earlier you can act, the better the outcome.
Treatment of hypothermia in lambs
Treatment of the moderately hypothermic lamb includes drying the lamb if it is wet, feeding colostrum by stomach tube and moving the ewe plus lamb(s) to a sheltered environment.
The use of artificial heat and separation of the lamb from its mother is usually unnecessary. In fact, if the latter happens it may well upset the bond between the ewe and lamb.
The lamb also becomes deficient in glucose if it becomes severely hypothermic after the first five hours of its life. Research suggests that death from cerebral hypoglycaemia (glucose deficiency in the brain) is still likely even if the lamb is warmed up from this state.
The glucose deficiency needs to be corrected by the administration of an intraperitoneal glucose injection. This involves the injection of a 20pc warm glucose solution into the abdomen of the lamb at a rate of 10ml/kg lamb birth weight.